Apparatus for withdrawing tubular objects from a mold



Aug. 29, 1961 H. D. BOGGS EIAL 2,997,737

APPARATUS FOR WITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28,1956 4 Sheets-Sheet 1 FIG].

INVENTORS HerZer?.D..Bo s Bea L,Mdf0 r7, /r

4 Sheets-Sheet 2 I II/ H. D. BOGGS ETAL IZI/A/ mvsmons //e Jeri 3.5

APPARATUS FOR WITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28,1956 Aug. 29, 1961 O S F-ea Llfd fo glr ATTORNEYS APPARATUS FORWITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28, 1956 Aug. 29,1961 H. D. BOGGS ET AL 4 Sheets-Sheet 3 s? umn @H WMEWH n QN 2? T! E ncwmv L gm 3 A QHQ Aug. 29, 1961 H. D. BOGGS ET AL APPARATUS FORWITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28, 1956 4Sheets-Sheet 4 United States l atent APPARATUS FOR .WITHDRAWING TUBULAROBJECTS'FROM A MOLD Herbert Briggs and Fred L. Magoon, Jr., Tulsa, Okla,

assignors, by mesne'assignments, to H. D. Boggs Company, Ltd., Omaha,Nebn, a limited partnership FiledJun'e 28, 1956, Ser. No. 594,565Claims. (Cl. 18-2) This invention relates to apparatus for removingnewly cast pipe from a casting mold.

More particularly, this invention relates to apparatus which isconstructed and arranged to service a plurality of pipe casting molds byproviding means for axially withdrawing newly cast pipe from each ofsaid molds after the casting operation has been completed.

While the apparatus which will now be described is particularly adaptedfor use in connection with the axial withdrawal of newly cast fibrouslyreinforced plastic pipe from its casting molds, it should be understoodthat this apparatus would be similarly suitable for use in connectionwith the withdrawal of other types of pipe from cylindrical molds.

It is therefore an object of this invention to provide apparatus foraxially withdrawing newly cast plastic pipe from a casting mold.

It is a further object of this invention to provide separate butco-operating means to first break the grip between a mold and a pipethat has been cast therein and to then withdraw the pipe from the mold.

It is another object of this invention to provide such apparatus whichcan service a number of casting molds which are aligned in a row, andwhich will allow the axial withdrawal of newly cast pipe without movingany of those molds from their aligned positions.

These and other o-bjects of this invention will be fully understood fromthe following detailed description of a typical preferred form andapplication of the invention, throughout which description reference ismade to the accompanying drawings in which:

FIGURE 1 is an elevational view, partially in section, of a cylindricalmold used for the centrifugal casting of P 1 FIGURE 2 is an'elevationalview of the pipe-ejecting assembly;

FIGURE 3' is a plan View of the pipe-ejecting assembly;

FIGURE 4 is a section taken along lines 4'4 of FIG- URE 3; and,

FIGURE 5 is a section taken along lines 55 of FIGU-RLY 4.

In FIGURE 1' there is shown a pipe casting assembly, generally indicatedat 76, which includes a pipe casting mold 162 mounted for rotationwithin the pipe casting assembly on bearings163; At one end of the mold,that is to say the end of the mold from which the newly cast pipe willbe withdrawn, the mold 162 is counter-bored, at 165, and interiorlyfitted with an annular collar 166, which is exteriorly dimensioned tofit into the counterbore, and has an interior diameter equal to the boreof the remainder of themold A v If the pipe to be cast is to have oneend exteriorly threaded, the collar I66 may'have a threaded interior soas to act as a thread mold.

2,557,737 Patented Aug. 29, 1961 The mold illustrated in FIGURE 1 isoccupied by a newly cast length of plastic pipe 355.

Referring to FIGURES 2, 3 and 4, it will be seen that the pipe ejectingassembly, generally indicated at 268, includes an elongated base frame,generally indicated at 270, which is mounted on flanged wheels 272 formovement alongrelatively transversely extending fixed rails 274, so thatthe entire pipe ejecting assembly can be transversely moved between anumber of positions corresponding to a number of the casting moldassemblies, generally indicated at 76.

Ina preferred embodiment, the transverse movement of the entire pipeejecting assembly 268 is selectively controlled by hand operatedsprocket wheel 278 which is connected by chain drive 280 to a sprocket282 on the shaft 284, upon which the wheels 272 are non-rotatablymounted. As will be evident hereinafter, it is quite important that theentire pipe ejecting assembly 268 be properly aligned with the axis ofthe particular mold which it is to service. The means for attaining thisexact alignment include an air lock assembly, generally indicated at286, which includes a pneumatic cylinder 288 having a piston rod 290maintained in a position to selectively engage an aperture in one of therails 274 when the pneumatic cylinder is suitably energized by operationof valve 296 on operating panel 298. The web of the rail 278 has anaperture drilled therein, at the same level as the piston rod 290, forevery mold 76 which is to be served by the pipe ejecting assembly, andthus when the rod 290 enters such an aperture the pipe-ejecting assemblyis properly aligned with a casting mold.

The transversely movable base frame 270, which consists essentially of apair of suitably braced, longitudinally extending, spaced parallel rails300, which may be formed of I-beams or the like, has a second frame,generally indicated at 302, which consists essentially of apair ofsuitably braced, longitudinally extending, spaced parallel rails 304,which may be formed of I-beams or the like, mounted thereon. The secondframe 302 is supported on flange wheels 306 which are arranged to rollalong rails 300 when the second frame is moved longitudinally of thebase frame 270. Such movement is obtained by a pneumatic cylinder 308,depending from the second frame 302, having the free end of its pistonrod 310 fixed to a fixed upstanding member 312 on the base frame 270.The pneumatic cylinder 308 is double acting and is coupled, by suitablelines, to a three-way control valve 314 located on the operating panel298.

A pipe-ejecting carriage, generally indicated at 316, is disposed uponthe rails 304 to move longitudinally thereof on wheels 318. Thepipe-ejecting carriage 316 is positively actuated to move longitudinallyof second frame 302 by a chain drive 320 extending longitudinally of therails 304, and approximately midway therebetween, at a level slightlybelow their upper surface. The chain drive 320 is secured, at each end,to the pipe-ejecting carriage 316, as by draw bolts 322 (FIGURE 4), andextends around an idler sprocket 324 mounted at the mold end of therails 304 and around a power sprocket 3'26 mounted at the opposite endof these rails. The power sprocket 326 is non-rotatably fixed to theshaft of reversible air motor 332, which is remotely controlled by afourway valve 334 located on the operating panel 298.

As the pipe-ejecting carriage 316 serves to convey a section of newlyformed plastic pipe 335, there are provided several pipe-supportingrollers 336 to bear the weight of, and to support, the pipe during theperiods when it is on, or partially on, the pipe ejecting assembly 268.These pipe-supporting rollers are, when in their operative position,located midway between the rails 304 and at a level slightly below thesurface thereof.

Each set of rollers 336 consists of an opposed pair of spaced coaxialtruncated conical rollers having their minor ends facing each other. Asbest shown in FIGURE 2, when the pipe-supporting rollers 336 areoperatively positioned at a level to support a newly formed pipe 335,and particularly a pipe of relatively small diameter, they willnecessarily be located along the longitudinal path of the pipe-ejectingcarriage 316. It is therefore within the contemplation of this inventionto provide means for moving the pipe-supporting rollers 336 from theirusual position when the pipe-ejecting carriage passes by.

To effect this end, each of the rollers 336 are rotatably mounted at thefree end of one of two rocker arms 370 which extend, in spaced parallelrelation, radially outward from a rocker arm shaft 372 which isrotatably mounted in suitable bearings (not shown) to extend under, andtransversely of, the rails 304. An operating arm 376 is fixed to therocker arm 372 and extends radially thereof. In the preferred embodimentillustrated, this rocker arm is angularly displaced from the rocker arm370 and is pivotally connected to a drive rod 380 which is, in turn,connected with a piston rod 382 of pneumatic cylinder 384. The pneumaticcylinders 384 may be selectively operated from the operating panel 298at such times as the pipe-ejecting carriage 316 approaches a given setof pipe-supporting rollers 336, or, as in this preferred embodiment,this operation may be entirely automatic by the provision of suitablemechanically operated valves, such as are well known in the art and neednot be described in detail herein, which operate the pneu maticcylinders to lower the rollers 336 as the pipe-ejecting carriage 316approaches.

It should be noted that the opposed truncated ends of thepipe-supporting rollers 336 are spaced from one another a distancesufficient to allow clearance of the chain drive 320 when the opposedrollers move as a unit, through an arc defined by the movement of rockerarms 370. While the preferred embodiment illustrated in FIG- URES 2 and3 has two sets of pipe-supporting rollers 336, it should be understoodthat it may be desirable to provide additional sets of rollers,particularly when the pipe being ejected from the mold 162 is unusuallylong. In such a case, each set of pipe-supporting rollers would beprovided with a means for lowering the rollers below the path of thepassing pipe-ejecting carriage 316 which are similar to the means whichhave just been described.

Referring more particularly to FIGURE 4, mounted upon the pipe-ejectorcarriage 316 is a pipe-ejector pullout. As has been describedhereinbefore, the end of the pipe mold 162 nearest the pipe-ejectingassembly 268 is counterbored and loosely fitted with a reinforcingcollar 166, usually having an internal diameter equal to that of therest of the mold, although it may have a threaded interior if threadedpipe is being cast. Generally speaking, the pipe-ejector pulloutconsists of an axially expanding circular wedge which is inserted withinthe lumen of the newly formed pipe 335 and then expanded to bear againstthe inner periphery thereof. The pipe is not distorted or injured as ithas been cast in a closely fitted relation to the reinforcing collar166. A hydraulic jack mounted on the pipe-ejecting carriage is thenenergized to urge the expanded wedge, and the pipe and reinforcingcollar grasped thereby, toward the mold-ejecting carriage. The movementimparted by the hydraulic jack is relatively short, it being suflicientthat the entire length of newly cast pipe be moved a short distance soas to break the typical initial bond or adhesion between the pipe andthe mold 162. The pipe is then completely withdrawn from: the mold bythe use of a powerful winch to draw the pipe-ejecting carriage along therails 304. This apparatus will now be described in detail.

As shown in FIGURE 4, a cylindrical sleeve 400' mounted upon carriage316 has a snugly fitting operatingrod 402 extending therethrough. A tube404 is coaxially' cantilevered from the sleeve 400, and extends towardsthe mold assembly 76. The tube 404 has a longitudinally extending keyway406 therein and has an interior diameter somewhat greater than theexterior diameter of operating rod 402. Slidably mounted and keyed (bykey 407 fitting in keyway 406) within tube 404 is a sleeve 408 which isinteriorly dimensioned to receive the operating rod 402 and has at leasta portion of its lumen interiorly threaded to engage raised threads 410formed upon a portion of the operating rod. The free end of theoperating rod nearest the mold assembly 76 is reduced and formed with atruncated conical projection 412 which flares outwardly toward the freeend thereof. The opposite end of the operating rod extends through ahollow hydraulic jack, generally indicated at 414, and has an operatingwheel 416 fixed on the extreme end.

The conical projection 412 is provided with a segmental collar ringcomposed of four chordal elements 418 (FIG- URE 5) held together, andabout the conical projection, by a tension spring member 420 disposed ina peripheral groove 422. The segmental collar ring is formed with aninterior taper complementary with that of the conical projection 412 andhas an exterior peripheral surface defining a right cylinder. In apreferred embodiment, the exterior or peripheral surface of each chordalelement is formed with a number of fine serrations thereon so as to giveit a better grip on the interior periphery of the pipe 335, as will beexplained. In operation, the conical projection 412, circumscribed bythe segmental ring 418, is inserted within the end of the mold 162 andso located that the segmental ring is within the area thereof which isfitted with the reinforcing collar 166. Rotation of operating rod 402,by suitable manipulation of wheel 416, causes an axial movement thereofaway from the mold 162, due to the engagement of the thread 410 with thethreaded interior of keyed, and hence nonrotatable, sleeve 408. Thesegmental collar 418, which is biased by tension spring 420 to snuglyfit on the conical projection 412, moves towards the sleeve 408 untilits end abuts the planar end surfaces of the sleeve. Further axialmovement of the operating rod 402, and the conical projection 412, inthe same direction, will cause the respective elements of the segmentalring to ride up the conical element until its peripheral surfacecontacts the interior of the pipe 335. It will now be seen that oncesuch contact is made, further axial movement of the operating rod 402will serve to wedge the serrations on the peripheral surfaces of thesegmental ring 418 tightly against the interior of the newly cast pipe335. As has been pointed out hereinabove, the strong reinforcing collar166 snugly circumscribes this portion of the pipe 335, so there is nodanger of distorting or injuring the pipe as long as reasonable forcesare used. It will now be understood that the minor interior diameter ofthe conical projection 412 must be less than the interior diameter ofthe free end of the sleeve 408, so that the end of the segmental ringwill properly abut the latter.

At this time the hollow hydraulic jack 414 is energized to urge the hub420 of the operating wheel 416 away from the pipe-ejecting carriage 316.This movement will be experienced by the conical projection 412 and thesegmental ring 418 and will tend to pull the pipe 335 out of the mold162. As has been stated hereinbefore, this movement is only for a verylimited distance, it being quite sutficient that the pipe be movedenough to break the bond or adhesion between the newly cast pipe 335 andthe mold 162.

I As shown'in FIGURES2 and 3, awincli 430", powered by prime mover 432,is mounted atthe' end of second frame 302 furtherest fromthe moldassembly 76, and a cable 436 is rove about the winch. The free end ofthe cable 436 is fitted on pipe=ejecting carriage 316 and is utilized todraw the latter along rails 304, and, hence withdraw the newly cast pipe335 from the mold 162 after the hydraulic jack 414-has beenoperatedtobreak the initial bond or adhesion between the pipe and the mold. Whenthe winch is being operated, the reversible air motor 332 is vented bytheoperajon of valve 334 so that the motor offers no resistance to thewinch. In a preferred embodiment, the operating controls 438 for thewinch may be located on the operating panel 298 alongside the valve 334.As the pipe-ejecting carriage moves away from the mold, thepipe-supporting rollers 336 will rise to their operative position toprovide suitable support for the length of the pipe 335 being withdrawnfrom the mold.

After the pipe has been completely withdrawn from the mold, theoperating wheel 416 is rotated to relax the grip of the segmental collarring 418 on the inner periphery of the pipe, in a manner that will nowbe understood, and then the pipe-ejecting carriage is moved moved awayfrom the pipe a distance sufficient to clear the conical projection 412and the segmental ring 418 from the interior of the pipe. The pipe isthen removed from the pipe-ejecting assembly 268, by any suitable means,and the pipe-ejecting carriage is moved back to the mold end of thesecond frame 302 by the air motor 332 and the chain 320 so as to beready to begin a new pipe-ejecting operation.

In FIGURES 2 and 3, the second frame 302 is illustrated as being sopositioned as to be spaced from the mold assembly 76, when the pipe 335is being withdrawn from the mold 162. It should be understoood, however,that when the hydraulic jack 414 is being operated to break the bondbetween the mold and the pipe, the mold end of the second frame 302 ispositioned to abut the end of the mold 162; otherwise the pulling forceof th jack would have a tendency to pull the mold 162 out of the moldassembly '76.

Having described only a typical preferred form and application of ourinvention, we do not wish to be limited or restricted to specificdetails herein set forth but wish to reserve to ourselves any variationsor modifications that may appear to those skilled in the art and fallingwithin the scope of the following claims.

We claim:

1. Apparatus for breaking the bond between an elongated hollow mold andan elongated hollow object cast therein, and for withdrawing the objectfrom the mold comprising: a first frame mounted for selective movementtransversely of the mold on a path adjacent the mouth thereof; a secondframe mounted for selective movement longitudinally of said first framein a direction parallel to the axis of the mold; carriage means mountedfor selective movement longitudinally of said second frame in adirection parallel to the axis of the mold; selectively operable hollowobject engaging means mounted on said carriage means; hydraulic meansmounted on said carriage to move said hollow object engaging meansaxially of said mold, and away therefrom, a short distance to break thebond between said mold and said hollow object, such movement beingindependent of said carriage means; and means for moving said carriagemeans, together with said engaging means, away from said mold towithdraw the hollow object from said mold.

2. Apparatus for breaking the bond between an elongated hollow mold andan elongated hollow object cast therein, and for withdrawing the objectfrom the mold comprising: a first frame mounted for selective movementtransversely of the mold on a path adjacent the mouth thereof; a secondframe mounted for selective movement longitudinally of said first framein a direction parallel to the axis of the mold; carriage means mountedfor seec ive mev mentz ona uslinally 9t aidse f me i a directionparallel tgthe of the mold; selectively operable hollow object engagingmeans: mounted on said carriage means; said hollowobject engaging meanscomprising a journal, an operating rod slidably mounted in said journaland extending therefrom in the direction of the mold alongan parallel tothat of the mold, a radial wedge defined by a portion of the operatingrod, said portion being without" said journal, radially expandng meansmounted on-saidwedge to radially expand upon axial movement of said-rodrelativeto said means, threads formed on another portion of saidoperating rod, said portion being without said journal, a nut threadablyengaged with said threads, said nut being fixed against rotation andfree to move axially relative to said journal; hydraulic means operableupon the engagement of said radially expanding means with the interiorof the hollow object cast therein to move said operating rod axially ofsaid mold, and away therefrom, a short distance to break the bondbetween said mold and said hollow object, said movement beingindependent of such journal; and means for moving said carriage means,together with said hollow object engaging means away from said mold toWithdraw the hollow object from said mold.

3. Apparatus for breaking the bond between an elongated hollow mold andan elongated hollow object cast therein, and for withdrawing the objectfrom the mold comprising: carriage means mounted for selective movementlongitudinally of said mold along a path axially aligned with the mold;selectively operable hollow object engaging means mounted on saidcarriage means; said hollow object engaging means comprising a journal,an operating rod slidably mounted in said journal and extendingtherefrom in the direction of the mold along an axis parallel to that ofthe mold, a radial wedge defined by a portion of the operating rod, saidportion being without said journal, radially expanding means mounted onsaid wedge to radially expand upon axial movement of said rod relativeto said means, threads formed on another portion of said operating rod,said portion being without said journal, a nut threadably engaged withsaid threads, said nut being fixed against rotation and free to moveaxially relative to said journal; hydraulic means operable upon theengagement of said radially expanding means with the interior of thehollow object cast therein to move said operating rod axially of saidmold, and away therefrom, a short distance to break the bond betweensaid mold and said hollow object, said movement being independent ofsuch journal; and means for moving said carriage means, together withsaid hollow object engaging means away from said mold to withdraw thehollow object from said mold.

4. The structure defined in claim 1 wherein said hollow object engagingmeans comprises an operating rod, an expanding gripping means located atone end of said rod, and means for expanding said expanding grippingmeans into gripping contact with the interior of the hollow object inresponse to rotation of said rod.

5. The structure defined in claim 4 and further including threads uponthe surface of said operating rod, means co-acting with said threads toconvert rotation of said rod into axial movement of said rod relative tosaid carriage to expand said expanding gripping means.

References Cited in the file of this patent UNITED STATES PATENTS859,656 Harbaugh et a1. July 9, 1907 889,31l Jones June 2, 19081,088,100 Saunders et a1 Feb. 24, 1914 1,455,686 Wallace May 15, 19231,499,620 Ladd July 1, 1924 (Other references on following page) 7UNITED STATES PATENTS Ladd July 1, 1924 Murray July 13, 1926 Ball Nov.16, 1926 D011 July 10, 1928 Ladd Aug. 6, 1929 Ladd Sept. 3, 1929Carrington Sept. 23, 1930 Krissiep Oct. 28, 1930 Mathieu June 16, 1931Weir Sept. 1, 1931 8 Barr et a1. May 29, 1934 Trotzke Aug. 12, 1941Williams Aug. 12, 1952 Iobe Dec. 30, 1952 Trout et a1. Apr. 13, 1954Hemm Apr. 20, 1954 Chanlund Feb. 21, 1956 Shatalofi May 29, 1956 LigonJan. 29, 1957 FOREIGN PATENTS Great Britain Mar. 28, 1935

